New Zealand's opposition National have kicked off their election campaign in Auckland with an American-style rally, pledging to change the government on October 14.

On Father's Day, opposition leader Chris Luxon was introduced by his children Olivia and William, who backed their dad to be the next prime minister.

The big-budget affair included a three-minute campaign ad to introduce Mr Luxon, beginning with an ominous image of sands emptying from an hourglass with the soundtrack of a ticking clock.

"New Zealand is running out of time," Mr Luxon says down the barrel.

"Every minute Kiwis are paying $234,000 in taxes. Every hour Labour is spending $16 million of your money.

"And every day New Zealand remains in recession. It's time for Kiwis to make a choice."

Almost 1000 National supporters flocked to Manukau in south Auckland for the campaign launch on Sunday, the party's biggest set piece on the road to polling day.

In contrast to Labour's campaign held the previous day, National was able to keep out anti-vax protesters, who waved signs outside but did not infiltrate the occasion.

Both Prime Minister Chris Hipkins and former leader Helen Clark had speeches interrupted by protesters as they launched Labour's campaign in central Auckland on Saturday.

While Ms Clark was the opening act to Mr Hipkins, Mr Luxon gave the platform to his young adult children - a hallmark of American politics.

The pair have American accents, given their family was based in the US while Mr Luxon forged his career as an executive, at Unilever and then Air New Zealand.

"He is incredibly hardworking and driven by the passion to make things better for people, and this country," Olivia said.

"How do we know this? Because the man that we love and all that is the same person that you know. There is no difference between the public and private person," William added.

Mr Luxon chose a song by American rockers Royal Deluxe, "Day is Gonna Come", as his walk-on anthem, led by lyrics. "It's time to get going, it's time to move on".

If the launch had a distinctly American flavour, Mr Luxon's big announcement was a piece of old school Kiwi campaigning.

Rather than launch a policy on Sunday, National instead launched a "pledge card", a throwback campaign tool used most successfully by Ms Clark.

The pledge card is a postcard sized bit of campaign literature with a beaming Mr Luxon on one side, and National's core commitments on the other.

They are to; lower inflation and grow the economy, let you keep more of what you earn, build infrastructure, restore law & order, lift school achievement, cut health waiting times, support seniors, and deliver Net Zero Carbon by 2050.

"New Zealanders have had enough. They want a new direction," Mr Luxon said.

"So does National and today I'm putting my name to a pledge guaranteeing eight commitments if National is elected on October 14."

In contrast, Labour unveiled a new policy to give free dental care for under 30s on Saturday.

On Sunday, the crowd's biggest cheer was for Mr Luxon's pledge to restore law and order, but otherwise, one veteran journalist described the atmosphere as "flat as a pancake".

The lack of enthusiasm was surprising given National is in the driver's seat to win the election.

Most recent polls have National on track to end six years of Labour-led governments, and form its own coalition with the right-wing ACT party.